Proxim plans to introduce today a wireless LAN switch and access point (AP) designed to support voice over WLANs as well as seamless handoffs between cellular and Wi-Fi networks:The switch and AP incorporate a number of functions that aim to make it easier for companies to deploy voice on their wireless networks.
For example, Proxim tackles the fast roaming issue through pre-authentication. Today, handoff between standard 802.11 APs happens too slowly, resulting in jitter or dropped calls. Proxim cuts down on that handoff time by pre-authenticating users to nearby APs, said Lynn Lucas, director of product marketing for Proxim. Because the switch knows which APs are near the one a user is connected to, it pre-authenticates the user on the surrounding APs in anticipation of the user moving into the nearby coverage area.
The switch supports pre-802.11e, the standard designed for quality of service (QoS). Proxim's implementation of the QoS mechanism improves power management on handsets because the APs work to minimize the time the radio in the handset must wake up. Rather than communicating with the handset haphazardly, the AP waits to send certain information during the same time frame that that handset delivers voice packets to the AP.
The switch also does load balancing by shifting calls from one AP to another within range that may be less heavily loaded.
The new APs support 802.11a, 802.11b, and 802.11g. Like previous versions of Proxim APs, customers can dedicate one of the radios to repeating traffic as a bridge. The APs support WPA and are software upgradeable to AES and 802.11i. They include rogue detection at both 2.4 Ghz and 5 Ghz for both 802.11b/g and 802.11a.
Proxim is also marketing this platform for its ability to support seamless handoff from cellular to Wi-Fi networks, yet the switch and APs are just one piece of the puzzle that will enable such integration. "Seamless mobility is not something that one company can realize," said Lucas. "Our portion of the solution which we'll be introducing is the switch." Proxim partners Motorola and Avaya are working on other components.
Before cell phone users can roam from the wide area networks to a WLAN, they'll need combined handsets and support from the cell operators, neither of which is in place yet. "Our message to the enterprise is that this is coming," Lucas said. IT managers typically look five years out when making technology investments so buying a switch that supports voice and integration with cell networks now makes sense, she said.
The switch facilitates handoff between a cellular and Wi-Fi network with functions such as handoff prediction and call setup based on the location of APs.